On March 17 the RapidScat instrument aboard the International Space Station (ISS) measured Bavi's surface winds from 01:28 to 3:01 UTC. RapidScat data showed surface winds were strongest winds in the northwestern quadrant. Sustained winds were near 17 m/s (38 mph/61 kph) and weaker around the rest of the storm.

On March 18 at 0000 UTC (March 17 at 8 p.m. EDT), the Joint Typhoon Warning Center noted that Bavi's maximum sustained winds dropped to 25 knots 28.7 mph/46.3 kph). It was located near 15.8 north latitude and 132.8 east longitude, approximately 489 nautical miles northwest of Yap, and was moving westward at 6 knots (6.9 mph/11.1 kph).

Bavi is moving west and weakening. The Joint Typhoon Warning Center expects Bavi to dissipate sometime on March 19.

Tropical Cyclone Bavi's convection and developing thunderstorms have been waning because of wind shear, and NASA's Aqua satellite provided an infrared look at the weakening storm.

The Atmospheric Infrared Sounder or AIRS instrument that flies aboard NASA's Aqua satellite revealed warming infrared temperature data of Tropical Cyclone Bavi's clouds on March 16 at 16:47 UTC (10:47 a.m. EDT). At 0900 UTC (5 a.m. EDT) on March 17, 2015 the Joint Typhoon Warning Center (JTWC) noted that "Recent animated enhanced infrared satellite imagery showed the system is stripped of any significant deep convection." That's as a result of moderate to strong (20 to 30 knot/23 to 34.5 mph/37 to 55.5 kph) southwesterly vertical wind shear. The imagery showed a ragged low-level circulation center and cloud top temperatures had warmed over the previous 24 hours. Warming cloud tops indicate that the cloud tops are dropping and the storms are weakening.

Bavi has weakened to a depression with maximum sustained winds near 30 knots (35 mph/55 kph). Bavi was centered near 15.6 north latitude and134.5 east longitude, about 784 nautical miles (902 miles/1,453 km) east of Manila, Philippines. Bavi was moving to the west-northwest at 8 knots (9.2 mph/14.8 kph).

Bavi is moving to the west, tracking along the southern edge of a sub-tropical ridge (elongated area) of high pressure to the north. The JTWC expects Bavi to dissipate in the next day or two.

NASA's Aqua satellite captured visible and infrared data on Tropical Cyclone Bavi as it moved in a westward motion through the Philippine Sea.

On March 16 at 01:35 UTC, the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument aboard Aqua provided a visible image of the storm. The storm appeared somewhat elongated with strong thunderstorms stretching from the center, northwest of the center as a result of moderate southeasterly vertical wind shear.

An infrared image from the Atmospheric Infrared Sounder or AIRS instrument that also flies aboard Aqua revealed the coldest cloud top temperatures of powerful thunderstorms were as cold as -63F/-52C, indicating they have the potential for dropping heavy rainfall. Those thunderstorms circled the center and northwestern quadrant of the storm.

At 1500 UTC (11 a.m. EDT), Bavi's maximum sustained winds were near 40 knots (46 mph/74 kph). It was centered near 14.2 north latitude and 138.4 east longitude, about 254 nautical miles north of Ulithi. Ulithi is an atoll located in the Caroline Islands.

Bavi was moving to the west-northwestward at 8 knots (9.2 mph/14.8 kph).

Bavi is forecast to continue on a westerly trek through the Philippine Sea, but is expected to weaken to a depression as it nears the northern Philippines. The Joint Typhoon Warning Center current forecast track takes the storm near eastern Luzon sometime on March 20.

NASA's Aqua satellite passed over Tropical Storm Bavi as it continued on a west-northwesterly track through the Northwestern Pacific Ocean. Bavi has already generated a typhoon watch for Guam, Rota, Tinian and Saipan.

The Atmospheric Infrared Sounder or AIRS instrument aboard NASA's Aqua satellite captured an image of Bavi on March 13. The image showed the eastern two-thirds of the storm and revealed strong thunderstorms around the center of circulation and a thick band of thunderstorms north of the center.

On March 13 at 1500 UTC (11 a.m. EDT), Tropical Storm Bavi had maximum sustained winds near 50 knots (57.5 mph/92.6 kph). It was centered about 851 nautical miles east-southeast of Andersen Air Force Base, Guam, near 9.7 north latitude and 128.8 east longitude. Bavi was moving to the west-northwest at 15 knots (17.2 mph/27.7 kph) and is expected to continue in that general direction.

The Joint Typhoon Warning Center (JTWC) forecast calls for Bavi to strengthen to hurricane-force on March 16 after passing over Guam on March 15. The JTWC extended forecast track calls for Bavi to move into the Philippine Sean and approach the eastern Philippines as a typhoon by March 18.

After Tropical Storm Bavi formed in the Northwestern Pacific Ocean, NASA and the Japan Aerospace Exploration Agency's TRMM satellite passed overhead and found heavy rain occurring in the western quadrant of the storm. A tropical storm watch is in effect for Ujae and Enewetakin in the western Marshall Islands as Bavi nears.

The Tropical Rainfall Measuring Mission or TRMM satellite can calculate rainfall rates from space, and as it flew over Tropical Storm Bavi on March 12 at 1215 UTC (8:15 a.m. EDT), TRMM radar data showed heavy rain falling at over 1.4 inches (40 mm) per hour near the center of the storm, and moderate rainfall near 1 inch (25 mm) per hour in a wide band of thunderstorms west of the center. At the U.S. Naval Research Laboratory, TRMM data was overlaid on infrared cloud data from Japan's MTSAT-2 satellite to provide a complete look at the storm and the rainfall rates within. The cloud imagery shows a large, wide band of thunderstorms wrapping into the center of circulation from the northwestern quadrant.

At 1500 UTC (11 a.m. EDT) on March 12, Bavi had maximum sustained winds near 35 knots (40 mph/62 kph). It was moving to the west-northwest at 12 knots (13.8 mph/22.2 kph). Bavi was near 8.4 north latitude and 165.6 east longitude, about 229 nautical miles (263.5 miles/ 424.1 km) east-southeast of Ujelang.

The third tropical depression of the northwestern Pacific Ocean typhoon season has formed in eastern Micronesia as NASA-JAXA's GPM satellite gathered rainfall data on the developing storm.

A tropical storm watch was already in effect on March 11 for Ujae and Ailinglaplap atolls in the western Marshall Islands.

The Global Precipitation Measurement or GPM core satellite gathered rainfall data on TD03W when it passed overhead on March 11 at 16:21 UTC (12:21 p.m. EDT). GPM saw that the heaviest rainfall was occurring southwest of the center of circulation where rainfall rates were near 1.6 inches (40 mm) per hour.

On March 11 at 1500 UTC (11 a.m. EST), Tropical Depression 03W (TD03W) formed just 92 nautical miles south of Kwajalein, part of the Marshall Islands. The center of TD03W was located near 7.2 north latitude and 168.2 east longitude. TD03W's maximum sustained winds were near 30 knots (34.5 mph/55.5 kph). It was moving to the west at 18 knots (20 mph/33 kph) and is expected to become a tropical storm.